codeforces gym 101164 K Cutting 字符串hash

题意：给你两个字符串a，b，不区分大小写，将b分成三段，重新拼接，问是否能得到A；

思路：暴力枚举两个断点，然后check的时候需要字符串hash，O（1）复杂度N*N；

题目链接：传送门

#pragma comment(linker, "/STACK:1024000000,1024000000")
#include<iostream>
#include<cstdio>
#include<cmath>
#include<string>
#include<queue>
#include<algorithm>
#include<stack>
#include<cstring>
#include<vector>
#include<list>
#include<set>
#include<map>
using namespace std;
#define LL long long
#define pi (4*atan(1.0))
#define eps 1e-8
#define bug(x)  cout<<"bug"<<x<<endl;
const int N=5e3+,M=2e6+,inf=1e9+;
const LL INF=1e18+,mod=1e9+;

string a,b,c;
unsigned int ma[N][N],mc[N][N];
int check(int l1,int r1,int l2,int r2,int l3,int r3)
{
    int s=,e=r1-l1;
    if(ma[s][e]!=mc[l1][r1])return ;
    s=e+,e=s+r2-l2;
    if(ma[s][e]!=mc[l2][r2])return ;
    s=e+,e=s+r3-l3;
    if(ma[s][e]!=mc[l3][r3])return ;
    return ;
}
void output(int l1,int r1,int l2,int r2,int l3,int r3)
{
    for(int i=l1;i<=r1;i++)
        printf("%c",b[i]);
    printf("\n");
    for(int i=l2;i<=r2;i++)
        printf("%c",b[i]);
    printf("\n");
    for(int i=l3;i<=r3;i++)
        printf("%c",b[i]);
    printf("\n");
}
int main()
{
    cin>>a>>b;
    int n=a.size();c="";
    for(int i=;i<n;i++)
    if(a[i]>='A'&&a[i]<='Z')a[i]=a[i]-'A'+'a';
    for(int i=;i<n;i++)
    if(b[i]>='A'&&b[i]<='Z')c+=b[i]-'A'+'a';
    else c+=b[i];
    int tot=;
    for(int i=;i<n;i++)
    {
        unsigned int seed = ; // 31 131 1313 13131 131313 etc..
        unsigned int has= ;
        for(int j=i;j<n;j++)
        {
            has=has*seed+(a[j]);
            ma[i][j]=(has & 0x7FFFFFFF);
        }
    }
    for(int i=;i<n;i++)
    {
        unsigned int seed = ; // 31 131 1313 13131 131313 etc..
        unsigned int has= ;
        for(int j=i;j<n;j++)
        {
            has=has*seed+(c[j]);
            mc[i][j]=(has & 0x7FFFFFFF);
        }
    }
    for(int i=;i<=n-;i++)
    {
        for(int j=i;j<=n-;j++)
        {
            if(check(,i-,i,j,j+,n-))
            {
                printf("YES\n");
                output(,i-,i,j,j+,n-);
                return ;
            }
            if(check(,i-,j+,n-,i,j))
            {
                printf("YES\n");
                output(,i-,j+,n-,i,j);
                return ;
            }
            if(check(i,j,,i-,j+,n-))
            {
                printf("YES\n");
                output(i,j,,i-,j+,n-);
                return ;;
            }
            if(check(i,j,j+,n-,,i-))
            {
                printf("YES\n");
                output(i,j,j+,n-,,i-);
                return ;;
            }
            if(check(j+,n-,,i-,i,j))
            {
                printf("YES\n");
                output(j+,n-,,i-,i,j);
                return ;
            }
            if(check(j+,n-,i,j,,i-))
            {
                printf("YES\n");
                output(j+,n-,i,j,,i-);
                return ;;
            }
        }
    }
    printf("NO\n");
    return ;
}